At present, a phased array technology has a promising application prospect in subsequent millimeter wave communication, where a beam direction is adjustable, so that effects of strong winds, shaking, and the like can be resisted. Effects of a factor such as rain fade need to be considered in design and deployment of a microwave system; therefore, relatively high transmit power is usually configured. However, in an actual running process, the system mostly runs in a scenario having no rain, and if highest transmit power is used, a receiving end is saturated, thereby causing unnecessary power consumption.